January 8, 2013
05:30 PM (EST)

News Release Number: STScI-2013-02

NASA Space Telescopes See Weather Patterns in Brown Dwarf

January 8, 2013: Astronomers using NASA's Hubble and Spitzer space telescopes have probed
the stormy atmosphere of a brown dwarf named 2MASSJ22282889-431026, creating
the most detailed "weather map" yet for this class of cool, star-like orbs.
The forecast shows wind-driven, planet-sized clouds enshrouding these strange worlds.
Brown dwarfs form out of condensing gas, as stars do, but lack the mass to fuse
atoms and produce energy. Instead, these objects, which some call failed stars, are
more similar to gas planets with their complex, varied atmospheres. The new research
is a stepping stone toward a better understanding not only brown dwarfs, but also of
the atmospheres of planets beyond our solar system.

Hubble and Spitzer simultaneously watched the brown dwarf as its light varied in time,
brightening and dimming about every 90 minutes as the body rotated. Astronomers found
the timing of this change in brightness depended on whether they looked using different
wavelengths of infrared light. The variations are the result of different layers or
patches of material swirling around in the brown dwarf in windy storms as large as
Earth itself. Spitzer and Hubble see different atmospheric layers because certain
infrared wavelengths are blocked by vapors of water and methane high up, while other
infrared wavelengths emerge from much deeper layers. Daniel Apai, the principal
investigator of the research from the University of Arizona, Tucson, presented the
results at the American Astronomical Society meeting on January 8 in Long Beach, Calif.
A study describing the results, led by Esther Buenzli, also of the University of Arizona,
is published in the Astrophysical Journal Letters. For more information about this study, visit http://www.nasa.gov/spitzer .